Ferri- to ferro-magnetic transition in the martensitic phase of a Heusler alloy
Robert D. Shull, Lawrence H. Bennett, Virgil Provenzano, Y. N. Jin, Igor Levin, E. Della Torre
During the past decade the magnetic properties of Heusler alloys have been extensively studied, motivated in part by the observation of large magnetocaloric effect (MCE) peaks displayed by these alloys near room temperature. We present new data and elaborate a consistent mechanism to explain the complex hysteretic behavior of a Ni_50}Mn_35}In_15} Heusler alloy. The magnetization of this alloy is characterized by two critical temperatures. Below the lower critical temperature, the alloy is a ferrimagnetic martensite. Between the two critical temperatures, the alloy is ferromagnetic martensite. Above the higher critical temperature, it is a paramagnetic austenite. The transitions at both critical temperatures are first order. The ferri-to-ferromagnetic transition and the crystallographic transition explain the various facets observed in the M_ZFC} and M_FC} vs. T plots and their variations with increasing field. The model successfully explains the isothermal M vs. H loops near room temperature, whose behavior is strongly dependent on the initial state.
Physica B-Condensed Matter
ferrimagnet, ferromagnet, Heusler alloys, magnetic hysteresis, magneto-structural transformation
, Bennett, L.
, Provenzano, V.
, Jin, Y.
, Levin, I.
and Della Torre, E.
Ferri- to ferro-magnetic transition in the martensitic phase of a Heusler alloy, Physica B-Condensed Matter
(Accessed December 2, 2023)